#pragma once

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;

cv::Mat drawHist(cv::Mat src){

	/// Separate the image in 3 places ( B, G and R )
	vector<Mat> bgr_planes;
	split(src, bgr_planes);

	/// Establish the number of bins
	int histSize = 256;

	/// Set the ranges ( for B,G,R) )
	float range[] = { 0, 256 };
	const float* histRange = { range };

	bool uniform = true; bool accumulate = false;

	Mat b_hist, g_hist, r_hist;
	/*vector<Mat>Mat_ch; 
	Mat_ch.push_back(b_hist);
	Mat_ch.push_back(g_hist);
	Mat_ch.push_back(r_hist);*/

	/// Compute the histograms:
	//for (int i = 0;i < src.channels();i++) {
		//calcHist(&bgr_planes[i], 1, 0, Mat(), Mat_ch[i], 1, &histSize, &histRange, uniform, accumulate);
	//}
	if (src.channels() == 3) {
		calcHist(&bgr_planes[0], 1, 0, Mat(), b_hist, 1, &histSize, &histRange, uniform, accumulate);
		calcHist(&bgr_planes[1], 1, 0, Mat(), g_hist, 1, &histSize, &histRange, uniform, accumulate);
		calcHist(&bgr_planes[2], 1, 0, Mat(), r_hist, 1, &histSize, &histRange, uniform, accumulate);
	}
	else
		calcHist(&bgr_planes[0], 1, 0, Mat(), b_hist, 1, &histSize, &histRange, uniform, accumulate);

	// Draw the histograms for B, G and R
	int hist_w = 512; int hist_h = 400;
	int bin_w = cvRound((double)hist_w / histSize);

	Mat histImage(hist_h, hist_w, CV_8UC3, Scalar(0, 0, 0));

	/// Normalize the result to [ 0, histImage.rows ]
	if (src.channels() == 3) {
		normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());
		normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());
		normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());
	}
	else
		normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());
	/// Draw for each channel
	
	for (int i = 1; i < histSize; i++)
	{
		line(histImage, Point(bin_w*(i - 1), hist_h - cvRound(b_hist.at<float>(i - 1))),
			Point(bin_w*(i), hist_h - cvRound(b_hist.at<float>(i))),
			Scalar(255, 0, 0), 2, 8, 0);
		if (src.channels() == 3) {
			line(histImage, Point(bin_w*(i - 1), hist_h - cvRound(g_hist.at<float>(i - 1))),
				Point(bin_w*(i), hist_h - cvRound(g_hist.at<float>(i))),
				Scalar(0, 255, 0), 2, 8, 0);
			line(histImage, Point(bin_w*(i - 1), hist_h - cvRound(r_hist.at<float>(i - 1))),
				Point(bin_w*(i), hist_h - cvRound(r_hist.at<float>(i))),
				Scalar(0, 0, 255), 2, 8, 0);
		}
	}

	/// Display
	//namedWindow("calcHist Demo", CV_WINDOW_AUTOSIZE);
	//imshow("calcHist Demo", histImage);

	//waitKey(0);

	return histImage;
}
